The impact of noise on wildlife ranging from birds to whales to elk has been a growing focus of scientific study. Increasing evidence suggests that animals in natural settings modify their behavior, though sometimes only briefly, in response to human commotion.

But as is so common in America when it comes to science, the politicians know better.

According to the Times,

This month, park managers at the Grand Canyon proposed requiring the operators to shift gradually to quieter aircraft, fly higher above the North Rim and refrain from flying at dawn and dusk. Yet Senator John McCain, Republican of Arizona, introduced legislation last week that could forestall the park's plan....

Bill Hedden, the executive director of the Grant Canyon Trust, an Arizona environmental organization, denounced the McCain proposal. "This is an amendment that essentially gives the entire game away to the air tour operators," Mr. Hedden said. "It redefines what constitutes natural quiet and lets them do any thing they want."

Asked about the amendment, Brooke Buchanan, a spokeswoman for the senator, warned that tighter regulation by the Park Service "could dramatically threaten tourism jobs and the tax base in Northern Arizona."

All over America, park rangers are quietly working to make parks quieter, silencing generators, using electric vehicles, providing shuttle buses to get rid of private cars and even negotiating with the air force about sonic booms near the Everglades. But the right to fly noisy planes and helicopters low over the Grand Canyon is sacrosanct.